Valmiki Ramayana Yuddha Kanda Sarga 19 Shloka 31

आप्रमेयः unbounded, अयम: this, महोदधिः great ocean, सगरेण: by Sagara, खनितः excavated, महामतिः king of the great ocean, ज्ञात: race, रामस्य: Rama's, कार्यम् task, कर्तुम् to do, अर्हति: ought to.

"This immeasurable great ocean was excavated by Sagara (A King of the Ikshvaku dynasty). The great ocean needs to do the task of Rama who is of the same race."